[PATCH libXext] add ACLOCAL_AMFLAGS = -I m4 to make aclocal pick ax_gcc_builtin.m4

[Matthieu Herrb]

Signed-off-by: Matthieu Herrb <matthieu at herrb.eu>
---
 Makefile.am | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index b76bc6c..4f5c67d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,7 @@
 SUBDIRS = man src specs
 
+ACLOCAL_AMFLAGS = -I m4
+
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = xext.pc
 
-- 
2.21.0